Xiangbing Zhu

Reflector Design of Light Emitting Diode for Uniform Illuminance

At present, Light Emitting Diode (LED) has been widely used in many fields. As illumination requirements on certain occasions are strict, an optical structure must be designed to distribute light. In this study, we propose a freeform reflector design method for uniform illumination. According to the radiation characteristic of LED and the illumination requirements, a differential equation is established. The numerical solution of the equation can determine the positions of the points on the reflector. The coordinates of these points are input into three-dimensional modeling software to fit the reflector. The optical system has been simulated with a ray tracing method. The simulation result shows good uniformity of illumination. If we apply this method to one computer program, and then the computer finishes the preliminary design, it will significantly reduce the design time. It can also be used in reflector design for non-uniform illuminance.

Optical design of an adaptive front-lighting system with high energy efficiency

To meet the demands of safe and comfortable driving, we present a new design of a highly energy-efficient Adaptive Front-lighting System (AFS) that can automatically adjust the shape, range, and light distribution of the illumination. The AFS system consists of a lamp, a reflector, light pipes, a Digital Micromirror Device (DMD), a condenser, and a lens. Our simulations show that this system can achieve different beams, such as basic passing beams, town beams, motorway beams, and corner lighting. By using the second light pipe to collect light, the illumination efficiency is increased by 10 points, accordingly reducing the generated heat of the lighting system.